Apparatus for polishing razors and other articles



Nov. 9, 1937. c: F. ERN, JR 2,098,233

APPARATUS FOR POLISHING RAZORS AND OTHER ARTICLES Filed March 2 1936 s Sheets-Sheet 1 1 II I I INVENTOR Earl Fri drich Em Jr. 1 BY ATTORNEYI 0. F. ERN, JR-

Nov; 59, 1937.

APPARATUS FOR POLISHING RAZORS AND OTHER ARTICLES 3 Sheeis-Sheet 2 Filed March 28, 1936 .INVENTOR Earl Fri dvich Em, Jr.

ATTORNEY C. F. ERN. JR

Nov. 9, 1937.

APPARATUS FOR POLISHING RAZORS OTHER ARTICLES 3 Sheets-Sheet 3 Filed March 28, 1936 INVENTOR Fri drich Em, w. BY 7 ,1 I '1 v ATTORNEY Earl Patented Nov. 9, 1937 7 PATENT OFFICE APPARATUS FOR POLISHING EAZOBS AND DTHER ARTICLES Carl Friedrich Ern, Jr., Solingen-Wald, Germany Application March 28, 1936, Serial No. 71,889 In Germany April 2, 1935 it Claims. (01. 51-84) The invention relates to apparatus for grinding, rough-polishing, fine-polishing and sharpening on one and the same machine tools such as razors, razor blades, table knives, long knives (bread knives, kitchen knives), scissors and penknives.

In the well-known machines of this kind the grinding axles as a rule are placed on carriages in one plane.

Machines of this type have been heretofore proposed in which the grinding axles are supported on swinging levers but in all such known machines the arrangement of these swinging levers is such that with wear, or by the employ? ment of grinding wheels having diameters which vary from an established form of construction, the point of attack of the grinding wheels as regards the work also changes in the direction of height.

In the known machines the bearing points of the swinging levers moreover are stationary. since, according to the shape of the cross section of the work or according to the nature of the grinding to be done, the grinding wheels have to be made to attack at different points of the work, while in the known machines, however, there is no possibility of shifting the cutting point of the two grinding wheels to diiierent points of the work, only a special kind of tool can be ground on these machines at any time.

These difliculties have heretofore necessitated the use of a plurality of grinding machines, which at any time could only be used for one and the same shape of work or for definitegroups of work shapes.

One object of the present invention is to provide an apparatus wherein the distance of the hearing points of the two swinging levers carrying the grinding wheel from the central grinding plane and their length have such relationship with each other that the point of attack of the grinding wheels does not change its height with any of the grinding wheel diameters entering into consideration.

A further object is to provide means whereby the diameter of the grinding wheels can be grinding wheel decreases in diameter at each grinding, even if only by a small amount.

The invention moreover renders it possible, without changing the height at which the work is located, to produce different grinding shapes in one and the same machine. A razor, for instance, having a certain width can be ground concavely on wheels of a diameter of from 180 millimeters down to 30 millimeters without changing the height of location. -In this con- 10 nection the'thickness of the back of the blades always remains the same.

Another object of the invention is to obtain displaceabillty of the base bearings for the swinging levers carrying the grinding wheels, in the 15 horizontal direction in order to regulate the distance of the bearing points of the swinging levers from the central grinding plane.

By means of this adjustment the same cutting point of the radii of the grinding wheels is always eflected on different distances from the center line, that is to say, in connection with thicker work-pieces the Iulcrums may be pushed away farther from the center line, in connection with thinner ones they can be brought closer to the center line.

Still another object of the invention is to provide a special device for gripping or clamping the tool in order always to keep the same in the right grinding position. This then results in an additional possibility for carrying out under certain conditions in a fully automatic manner the entire grinding, polishing and sharpening operation.

Further details of the invention and the other characteristics, still essential for the same are shown by the following description of the form of embodiment represented in the drawings by way of example.

Figs. special relations between the length of the swinging levers and the distance of the fulcrums from the central grinding plane, 1. e. Fig. 1 in connection. with grinding wheels directly opposite each other for carrying out concave grinding work and the like, and Fig. 2 when using 1 and 2 diagrammatically show the 40 Figures 7 and 8 show in side view and in section respectively a pair of grinding wheels according to Fig. 2.

The grinding wheels which, as already emphasized, run either with or against each other and are opposite each other, separated by a distance of 0.2 millimeter, or which overlap, as shown by Figs. 7 and 8, are designated throughout by I, 2 in the drawings for the sake of simplicity. They are rotatively supported in the heads 3 of two swinging levers l, 5, being located on axles 6 which can turn in the swinging lever heads developed in. the shape of hubs. The swinging levers individually and in detail have the shape shown by Fig. 4, that is to say, they consist of double arms 4', 5' which run together in long hubs at the top and at the bottom.

0n the ends of axles 6 are pulleys I which are driven from a shaft 8 by means of a suitable belt transmission. The pulleys can be jointly operated in opposite directions by means of a single belt which is guided over a suitable reversing roller, which latter may serve at the same time as a belt tightener. The lower ends of the swinging levers are developed as hubs 3 and can rotate around pins 9 which are supported in carriages III A special characteristic of the invention conv sists oi the fact that the length of the swinging arms and the distance of the fulcrums from the central grinding plane have a special relation toeach other.

According to Fig. 1, it must be assumed that the straight line AA is given as the centralggrinding plane. Furthermore the point 'P and thus the vertical distance of the straight line AA which in Fig. 1 'is designated by Ah, is a given quantity. What is looked for are thecurvature centers of all circles which touch the straight line AA and pass through the point P.

For a circle corresponding to the diameter of a grinding wheel halving the radius r1, there results a distance $1 from the point of contact C with the straight line. The rectangular triangle PFC in which the distance 81 is the height, results in the relationship s1==Ah (21'1-Ah). For any other circle with the radius r there results for the same reason: s =Ah (2r-,Ah).

If the straight lines A-A and A'-A' are considered as the axle cross of a system of coordinates, s and r designate the corrdinates of the circle centers, and the equation to be derived s =Ah (2r--Ah) corresponds to the equation of the curve which represents the geometrical place for all the curvature centers entering into consideration. The equation corresponds to that of a parabola. The vertex of this parabola lies in the center of the vertical distance of the straight line AA from the point P.

As the arrangement of a parabola .guide is not very desirable for constructive reasons, the parabola in the practical execution of the machine is replaced by a circular are which, .within the scope of the stationary border cases for the diameter deviations, coincides with the shape of the parabola in a manner entirely adequate from a practical point of view.

The necessary measurements can be ascertained with the requisite accuracy both arithmetically and by means of drawings. For the arithmetical ascertainment no further instructions are necessary. Neither does the ascertainof the parabola by taking as a basis the given quantities and the replacement of the parabola piece entering into the question by a suitable circle arc afford any difllculties. The examples given in Figures 1 and 2 show the essential details. It is seen here that in connection with a radius of 350 millimeters on the part or the swinging levers and a distance of the fulcrums of the swinging levers from the central grinding plane of 112 millimeters within a scope of diameter changes of the grinding wheels of between to 50 millimeters, i. e., a very large interval, the effect according to the invention is obtained.

In order to be able to uniformly adjust the grinding wheels around their swinging points 9 with reference to the central grinding plane, the two swinging levers 4, 5 are engaged by guides I,

[2 which are rotatively supported at a common bearing place l3. The bearing place I3 is connected with an arm i5 carrying a hand wheel II. On the shaft of the hand wheel there is secured a bevel gear l6 which engages a second bevel gear i1 arranged on a spindle [8.

The spindle l8 engages a socket i9 provided with a suitable screw thread and secured on the machine frame.

When the hand wheel I is turned, the spindle I8 is displaced in the screw thread whereby the arm l5 carrying the bevel gears I 6, I I and the hand wheel [4 goes up or down together with the said bearing place [3 for the two guides ll, l2 and 2 thereby compulsorily and uniformly moves the two swinging levers I, 2 towards or away from each other with reference to the central grinding plane.

The hand adjustment is required in order to set the machine for the corresponding work in the first place. In addition to the hand adjustment an automatic adjustment is also provided in the example of execution for the two swinging levers 4, 5.

This automatic adjustment consists of a regulating shaft 2i coupled with the main driving shaft 80. and carrying a cam 20. The suitably constructed groove 22 of the cam 20 is engaged by a roller 23 which is connected with a rod 24 running through the already mentioned socket or bushing l9 and likewise raising or lowering the bearing arm i5 carrying the two bevel gears l6, l1 and the hand wheel'il or the bearing lit for the two guides ll,'|2. The fulcrums H and I2 for the guides II and i2 and the distance of these fulcrums from the bearing iii are chosen in such a way that when adjusting the swinging points 9, the bearing place I3 01" the two guides remains stationary.

The swinging points 9 of the two swinging levers are adjustable in the horizontal direction, the respective bearing pins resting on carriages I0 provided with teeth 26. The teeth or cogs 26 of the carriages are engaged by pinions 21 which are adjustable, for instance on each side by itself, by a hand wheel 28 etc.

The arrangement, however, can also be made in such a way that the two gears are coupled with each other by any intermediate gears and this coupling is disconnected, if only one of the base bearings of the swinging levers is to be adjusted in the horizontal direction.

The non-uniform displacement of the two carriages Ill only enters into consideration for such work as has a non-symmetrical cross sectionalshape, as, for instance, when grinding scissors, etc. I

The supporting of the work 30 (Fig. 4) is effected by means of a special clamping ,device which is constructed in a form peculiar to the clamping of the work in this machine.

The clamping device is moveable crosswise to the grinding wheels i. e., in a direction parallel to the axes of these wheels by means of a carriage guide in order to bring the difierent parts of the edge to be ground successively into engagement with the grinding tools. As a rule, a constant moving back and forth of the tools takes place during the entire grinding operation.

The drive of this reciprocal movement of the work carrier takes place by means of a lever 32 (Figure 4) rotatively supported in an extension 3| of the machine standard, which lever is driven by the main driving shaft via a cam-drive 33,-

34, 35. The slotted crank plate 33, 34 used in this drive is arranged adjustably so that the stroke of the carriage can be changed to adapt itself to the carrying lengths of the work.

The support 31 is moreover arranged so that it can go up and down. The extension 35' of the carriage 3'6 which engages the head of the lever 32, as well as the latter itself have for this purpose the embodiment shown by Fig. 4.

The supplementary device for changing the height of location of the work carrier 31 is constructed similarly to the adjusting'device I4 to IQ for the swinging levers 4, 5. It consists of a hand wheel 40 located, as shown by Figs. 3 and 4, above the hand wheel l4 and laterally thereof, this hand wheel 40 being secured on a shaft carrying the bevel gear 42. The bevel gear 42 engages a second bevel gear 4| resting on a spindle 43. The spindle in turn engages a corresponding spindle nut.

This adjusting device, too, is developed moreover in such a way that, independently of the above mentioned actuation by hand, it may also receive an automatic compulsory drive. This consists of a roller 44 arranged on an extended shank of the spindle and engaging the groove 45 of a cam 46 which is keyed on a shaft 48 and. the same as the cam 22, receives its drive through suitable gears. The ratios are indicated in Fig. 3 at 5|.

With the new machine not only it is possible to obtain a fully automatic operation for a definite manner of working, but several machines may be arranged according to the invention alongside or in back of each other and to each machine there may be assigned a special working operation, in such a way, for example, that in the first machine preliminary grinding is done, then in the next 'machine rough polishing is efiected and in an additional machine fine polishing takes place, while the work then receives the final sharpening in still another machine.

The conveying of the work through the different machines can be automatically effected by guiding the clamping device with the work in it successively through the different grinding or polishing machines. This is possible for instance on a carriage or slide track extending throughout all the machines. Under certain circumstances a conveying device may also be used which is connected with the driving mechanism of the machine and automatically conveys the work carriers after a certain working time in one machine to the next one, leaving it there for a suitable length of time and then passing it on to another machine.

In this construction the working times oi the work-piece in the diiierent machines can be varied by a suitable construction of the control cams according to the nature of the operation.

It is, of course, also possible to accomplish the various gradations which are necessary according to the nature of work in fully automatic .operation, by selecting a corresponding number of grinding, p lishing and sharpening machines.

What I claim is:

1. Machine for the grinding or polishing of tools of different cross sectional shapes, comprising grinding wheels arranged at opposite sides of a central grinding plane, two adjustable levers, bearings in said levers for the grinding wheels, pivot bearings for the levers, and means for swinging the levers to move the wheels through circular arcs of comparatively slight curvature,

the distance between the wheel bearing and the pivot bearing in each lever being substantially greater than the distance between the latter bearing and the said grinding plane, and the latter distance having such a ratio to the length of each lever that the point of contact of the grinding wheel with the tool remains constant in height for grinding wheels of differentdiameters.

2. Grinding machine according to claim 1, comprising a device for adjusting the swinging levers consisting of a pair of guides, a joint fulcrum for theguides, and means for the vertical adjustment of the fulcrum.

v3. Grinding machine according to claim '1, comprising means for adjusting the swinging levers consisting of a pair of guides, a fulcrum for the guides and bevel gears and a nut and screw spindle for raising and lowering the fulcrum.

4. Grinding machine according to claim 1, comprising adjusting means for the pivot bearings of the swinging levers to displace such bearings horizontally towards and away from the said grinding plane.

5. Grinding machine according to claim 1, comprising means for clamping the pivot bearings of the swinging levers and means for adjusting each of said bearings independently of the other in a direction at right angles to the central grinding plane.

6. Grinding machine according to claim 1, comprising a carriage supporting the bearing of each swinging lever, a toothed member on each carriage, and a toothed wheel engaging each of said members for adjusting the bearing of the swinging lever.

7. Grinding machine according to claim 1, comprising means for turning the swinging levers about their bearings, means for adjusting said grinding operation. a slotted crank plate for operating the said swinging member, and'means or varying the height of the tool carrier without- L -rrupting the reciprocation of the tool its carrier.

CARL FRIEDRICH ERN, JR. 

